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#21
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"Dark Helmet" wrote in message t... "Whisper" wrote in message ... So I conclude we will never know, but should endeavour to understand as much as possible & enjoy the short time we have...... Okay, then back to the original question. How can we on Earth be (or were) further from another object than light could travel since the big bang. Dark Helmet Duh. There was no 'big bang', & the speed of light is not the fastest thing in the universe. As I said, there are 'forces' we can't perceive & beyond human comprehension. Just accept it..... |
#22
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"Dark Helmet" wrote in message
... Suppose the nebula has been travelling away from us at 1/2 the speed of light. I have no idea what the relative velocity of these two entities would be, but I would assume this is on the extreme high-end. Let's assume we have maintained this relative velocity consistently since the light reaching us now originally left the nebula. Therefore, we would have been 9 billion light years away from the nebula 12 billion years ago. The light travelled for 12 billion years before reaching us, in which time we would have travelled 3 billion light years from our original point in space (each of us would be travelling at 1/4 the speed of light to get a relative velocity to each other of 1/2 the speed of light). Net, net, (if I did the right math?) at an assumed expansion rate of 1/2 the speed of light, we would have been 9 billion light years apart 12 billion years ago. Or we were 9 billion light years apart when the universe was 2 billion years old. No matter how you slice it, we have a paradox unless the big bang created initial velocities greater than the speed of light. Other thoughts? The big bang was not an explosion of matter into pre-existing space, it was an expansion of space itself. As such, it carried whatever was embedded in it along for the ride. So faster than light separation speeds were not a problem, and aren't now, for widely separated regions of space. Note that this does not mean that Special Relativity was "broken"; no bodies or light move faster than light within the local space where they are embedded. Separation speeds grow greater the further apart the regions of space are. This is because when space expands, it expands (to the best of our knowledge) uniformly at all points. So your numbers assuming constant separation speeds are not correct. The expansion also implies that there is what is called a "cosmic horizon" beyond which we cannot see and will never be able to see. The further we look, the faster things (and space) are receding. At some distance, depending upon the value of the Hubble constant, the speed of recession is the speed of light. Regions of space beyond that are separating from ours at greater than the speed of light. Light emitted in our direction from those regions can never reach us, for although the light is moving towards us at c in that local space, the space itself is carrying the light away at an even greater velocity. |
#23
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"Whisper" wrote in message
... Duh. There was no 'big bang', & the speed of light is not the fastest thing in the universe. As I said, there are 'forces' we can't perceive & beyond human comprehension. Just accept it..... And your evidence for the above is....? |
#24
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"Greg Neill" wrote in message .. . "Whisper" wrote in message ... Duh. There was no 'big bang', & the speed of light is not the fastest thing in the universe. As I said, there are 'forces' we can't perceive & beyond human comprehension. Just accept it..... And your evidence for the above is....? He can't tell you his evidence... because you couldn't comprehend it! Isn't that convenient! |
#25
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The oldest object in the universe is the proton. Hope someone can prove
me wrong. Bert |
#26
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"Greg Neill" wrote in message
.. . The big bang was not an explosion of matter into pre-existing space, it was an expansion of space itself. As such, it carried whatever was embedded in it along for the ride. So faster than light separation speeds were not a problem, and aren't now, for widely separated regions of space. Note that this does not mean that Special Relativity was "broken"; no bodies or light move faster than light within the local space where they are embedded. Separation speeds grow greater the further apart the regions of space are. This is because when space expands, it expands (to the best of our knowledge) uniformly at all points. So your numbers assuming constant separation speeds are not correct. The expansion also implies that there is what is called a "cosmic horizon" beyond which we cannot see and will never be able to see. The further we look, the faster things (and space) are receding. At some distance, depending upon the value of the Hubble constant, the speed of recession is the speed of light. Regions of space beyond that are separating from ours at greater than the speed of light. Light emitted in our direction from those regions can never reach us, for although the light is moving towards us at c in that local space, the space itself is carrying the light away at an even greater velocity. Greg, this makes a lot of sense. Thanks for taking the time to do this. Now, this leads me to a few more questions. First, what exactly is space then that allows it to expand faster than than the speed of light? Second, since light is travelling through expanding space and all space is expanding, would light only travel at a relative speed of c in an infinitesimally small area of space? For example, light leaving my monitor screen at this moment is in a portion of space that is expanding away from me, although small, so this light will really not reach me at a true speed of c. Thoughts? Happy Holidays, Dark Helmet |
#27
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"Dark Helmet" wrote in message
t... Greg, this makes a lot of sense. Thanks for taking the time to do this. Now, this leads me to a few more questions. First, what exactly is space then that allows it to expand faster than than the speed of light? Well, that's the $64,000 question. A definitive answer to that would require a grand unifying Theory of Everything. The best we can do right now is turn to the General Theory of Relativity and Maxwell's equations for its properties. It boils down to a handful of properties, such as permitivity and permeability and curvature. It has no mass, stiffness, or other mechanical properties. Second, since light is travelling through expanding space and all space is expanding, would light only travel at a relative speed of c in an infinitesimally small area of space? For example, light leaving my monitor screen at this moment is in a portion of space that is expanding away from me, although small, so this light will really not reach me at a true speed of c. Thoughts? You would measure a difference in speed if the space between you and your monitor were expanding. Alas, it is not. The space occupied by gravitationally bound systems does not participate in the overall expansion. That means that the space encompassing us, the planet, the solar system, the galaxy, and the local galactic cluster is not participating in the expansion. |
#28
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If you were to bet your life as to what is the oldest object in the
universe. You would stay alive by saying the "proton" Bert |
#29
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If mini-bangs can make the universe continuos we will see galaxies that
are very old.(older than our mini-bang that created our universe.) I read we have found some of these ancient galaxies. Astronomers don't like the idea the universe is younger than some of its parts. They should think about it using mini-bangs instead of fudging. My thoughts would predict these ancient galaxies would be very far away,and might be so old that they are falling apart. Might be made mostly of brown dwarfs,white dwarfs,and telling us what the Milky Way will look like 22 billion years from now. Bert |
#30
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"G=EMC^2 Glazier" wrote in message
... If you were to bet your life as to what is the oldest object in the universe. You would stay alive by saying the "proton" Bert Why not the quarks that comprise protons? Or maybe photons or neutrinos, they would not have had to wait for the temperature to drop sufficiently to form bound states. |
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